XVI International Botanical Congess

Different explants (seed, mature embryo, 3-day and 6-day old leaf/mesophyll joint) of seven oat varieties (Matilda, Adamo, Belinda, Birgitta, Freja, Petra and Stork) were placed on 2,4 -D containing callus induction medium. After about 4 weeks explants were evaluated for callus growth. In all varieties maximum growth was obtained from mature embryos. Shoot regeneration could be obtained from Belinda (mature embryo, 3-day and 6-day old leaf/mesophyll joint), Birgitta (3-day old leaf/mesophyll joint), Stork (mature embryo and 3-day old leaf/mesophyll joint) and Matilda (3-day old leaf/mesophyll joint) in a medium with auxin/cytokinin combination. This was followed by root generation in a hormone free medium. Different explants of Matilda variety was cocultivated with Agrobacterium tumefaciens carrying a binary 35::uidA vector construct. Histochemical GUS staining of early callus/tissue showed an initial general GUS activity that after about 3 weeks focussed to discrete regions.